Enzymatic hydrolysis of DNA using a membrane bioreactor

Aim of this work was a kinetic study of the deoxyribonuclease I (E.C. 3.1.21.1.) reaction in several conditions. Optimal reaction conditions with enzyme free in solution were determined. DNase activity was studied as function of several parameters such as pH, enzyme concentration, substrate concentration, cofactor concentration. The Km value of the free enzyme was also determined. Subsequently, the possibility to carry out the reaction in systems in which the enzyme was immobilized on the inner surface of the polymeric membranes was evaluated and realized. Experimental procedures, in these new conditions, permitted to determine the mass of immobilized enzyme and the percentage of the reaction product recovery. Results showed that the immobilization procedure determines a decay of the initial activity of enzyme, but there is an important increase of enzyme stability.